Publications

lactoferrin protects rabbits from shigella flexneri-induced inflammatory enteritis.	shigella species cause bacillary dysentery in humans by invasion, intracellular multiplication, spread to adjacent cells, and induction of brisk inflammatory responses in the intestinal epithelium. in vitro data suggest that lactoferrin, a glycoprotein present in human mucosal secretions, has a role in protection from bacterial enteric infections. we sought to determine the activity of lactoferrin in vivo, using the concentration present in human colostrum, to investigate its effect on the devel ...	2002	12438385
evolution of multiresistance in nontyphoid salmonella serovars from 1984 to 1998 in argentina.	molecular evolution of multiresistance in nontyphoid salmonella spp. was investigated with 155 isolates obtained in argentina from 1984 to 1998. in 74 isolates obtained from 1984 to 1988 resistance was associated with the presence of tn3, tn9, class i (in0) and ii (tn7) integrons, and the aac(3)-iia gene. extended-spectrum cephalosporin (esc) resistance in salmonella spp. emerged in 1989, and 81 isolates resistant to at least one esc and one aminoglycoside were collected thereafter. among these, ...	2002	12435702
[comparison of shigella susceptibility to commonly used antimicrobials in the temuco regional hospital, chile 1990 - 2001].	the permanent surveillance of antimicrobial susceptibility of shigella sp in the temuco regional hospital, allowed us to define the empirical use of antimicrobials in dysenteric syndrome.	2002	12434650
structure-function analysis of invasion plasmid antigen c (ipac) from shigella flexneri.	shigella flexneri causes a self-limiting gastroenteritis in humans, characterized by severe localized inflammation and ulceration of the colonic mucosa. shigellosis most often targets young children in underdeveloped countries. invasion plasmid antigen c (ipac) has been identified as the primary effector protein for shigella invasion of epithelial cells. although an initial model of ipac function has been developed, no detailed structural information is available that could assist in a better un ...	2003	12427760
molecular recognition of oligosaccharide epitopes by a monoclonal fab specific for shigella flexneri y lipopolysaccharide: x-ray structures and thermodynamics.	the antigenic recognition of shigella flexneri o-polysaccharide, which consists of a repeating unit abcd [-->2)-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->], by the monoclonal antibody sya/j6 (igg3, kappa) has been investigated by crystallographic analysis of the fab domain and its two complexes with two antigen segments (a pentasaccharide rha a-rha b-rha c-glcnac d-rha a' and a modified trisaccharide rha b-rha c-glcnac d in which rha c* is missing a c2-oh ...	2002	12427018
shigella isolation in vellore, south india (1997-2001).	shigellosis has been a major cause of dysentery for many years at vellore, south india. in the last two years the number of shigella being isolated from samples of faeces from patients with diarrhoea has decreased (5% isolation rate in 1997 to 3.9% in 2001), although the microbiological methods and media used have not changed. also, the nalidixic acid (na) resistance has increased for s. sonnei (now 94%). this is noteworthy, since na has been recommended for the empirical treatment of patients s ...	2002	12424931
shigella flexneri bacteraemia in an immunocompetent male treated with oral ciprofloxacin.		2002	12423618
[acute diarrhea outbreak caused by shigella flexneri at a school in madrid, cundinamarca: phenotypic and genotypic characterization of the isolates].	shigellosis is an acute diarrhoeal disease that is the main cause of morbidity and mortality in developing countries. in 1997, the colombian instituto nacional de salud microbiology group organized a network surveillance program with the country's public health laboratories (phls) to monitor the principal etiological agents responsible for acute diarrhoeal disease. in may, 2001, the phl of the state of cundinamarca reported a food poisoning outbreak involving an elementary school community. the ...	2002	12404927
[the role of hla-b27 molecules in the pathogenesis of ankylosing spondylitis].	ankylosing spondylitis (as) is characterised by the strongest association with an hla antigen ever described for any disease. it represents therefore the ideal model for the understanding of the link between immune-mediated diseases and the hla system. the role of hla-b27 in the pathogenesis of as will be discussed focusing on the recently described higher expression of these molecules in patients with as compared with healthy controls.	2002	12404037
doc-mediated cell killing in shigella flexneri using a c1/laci controlled expression system.	in this report we describe the development of a highly stringent and dually regulated promoter system for shigella flexneri. dual regulation was provided by utilizing a promoter susceptible to control by the bacteriophage p1 temperature-sensitive c1 repressor that in turn was under the transcriptional control of laci. the level of induction/repression ratios observed was up to 3700-fold in s. flexneri. the general utility of this promoter system was evaluated by demonstrating that the bacterioph ...	2002	12399040
selection of shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm.	we describe an in vivo expression technology (ivet)-like approach, which uses antibiotic resistance for selection, to identify shigella flexneri genes specifically activated in bacteria resident in host cell cytoplasm. this procedure required construction of a promoter-trap vector containing a synthetic operon between the promoterless chloramphenicol acetyl transferase (cat) and lacz genes and construction of a library of plasmids carrying transcriptional fusions between s. flexneri genomic frag ...	2002	12390353
genome sequence of shigella flexneri 2a: insights into pathogenicity through comparison with genomes of escherichia coli k12 and o157.	we have sequenced the genome of shigella flexneri serotype 2a, the most prevalent species and serotype that causes bacillary dysentery or shigellosis in man. the whole genome is composed of a 4 607 203 bp chromosome and a 221 618 bp virulence plasmid, designated pcp301. while the plasmid shows minor divergence from that sequenced in serotype 5a, striking characteristics of the chromosome have been revealed. the s.flexneri chromosome has, astonishingly, 314 is elements, more than 7-fold over thos ...	2002	12384590
genetics of isoprenoid biosynthesis in paracoccus zeaxanthinifaciens.	the genes coding for all the enzymes involved in the conversion of acetyl-coa to farnesyl diphosphate (fpp) in the zeaxanthin-producing bacterium paracoccus zeaxanthinifaciens were cloned and characterized. two genes encoding enzymes catalysing the condensation of two acetyl-coa molecules to acetoacetyl-coa were found. the six enzymes involved in the conversion of acetyl-coa and acetoacetyl-coa to isopentenyl diphosphate (ipp) and dimethylallyl diphosphate (dmapp) are grouped in an operon, desig ...	2002	12384294
enteropathogens associated with acute diarrhea in community and hospital patients in jakarta, indonesia.	the prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from march 1997 through august 1999 in jakarta, indonesia was determined using routine bacteriology and molecular assay techniques. bacterial pathogens isolated from hospital patients were, in decreasing frequency, vibrio cholerae o1, shigella flexneri, salmonella spp. and campylobacter jejuni, while s. flexneri, v. cholerae o1, salmonella spp. and c. jejuni were isolated fr ...	2002	12381465
shigella flexneri degp facilitates icsa surface expression and is required for efficient intercellular spread.	a degp mutant of shigella flexneri was identified in a screen for insertion mutants that invaded cultured cells but did not form wild-type plaques in monolayers. the degp mutant sm1100 invaded henle cells at wild-type levels and induced apoptosis in macrophages but formed smaller plaques than those formed by wild-type s. flexneri in confluent monolayers of henle and caco-2 cells. the proportion of sm1100 bacteria with icsa localized to the bacterial pole, a process required for actin polymerizat ...	2002	12379715
septic shock associated with shigella flexneri dysentery.	septic shock is a very unusual presentation of shigella infection. we describe a 3-y-old child who developed severe septic shock and severe encephalopathy during an episode of dysentery caused by shigella flexneri.	2002	12374365
[dysentery in poland in 2000].	the notified number of dysentery cases is still falling down since the year 1995 when bacteriological examination of feces for diagnostic purposes lost free of charge status obtained in 1928 under the legislation act of infectious disease investigation and obligatory registration. only 121 dysentery cases were notified in the year 2000 (incidence 0.31/100,000 population), while 292 cases were notified in 1999 (incidence 0.76/100,000). no one death case was notified. only 2 outbreaks (one due to ...	2002	12371362
epithelial inflammation response induced by shigella flexneri depends on mucin gene expression.	the protective effects of different mucin gene profiles on gut protection were assessed by the evaluation of tnfalpha production by intestinal epithelial cells infected by shigella flexneri. three ht-29 cell lines were used: ht29-g(-) (enterocyte-like cells, secreting no mucins), ht29-fu (highly expressing muc2 and muc4) and ht29-mtx (highly expressing muc3 and muc5ac). these cells were infected either by an invasive (m90t) or the control isogenic (bs176) strains of s. flexneri, and tnfalpha mrn ...	2002	12361911
conversion of ptdins(4,5)p(2) into ptdins(5)p by the s.flexneri effector ipgd reorganizes host cell morphology.	phosphoinositides play a central role in the control of several cellular events including actin cytoskeleton organization. here we show that, upon infection of epithelial cells with the gram-negative pathogen shigella flexneri, the virulence factor ipgd is translocated directly into eukaryotic cells and acts as a potent inositol 4-phosphatase that specifically dephosphorylates phosphatidylinositol 4,5-bisphosphate [ptdins(4,5)p(2)] into phosphatidylinositol 5-monophosphate [ptdins(5)p] that then ...	2002	12356723
effect of organic acids and temperature on survival of shigella flexneri in broth at ph 4.	the survival of bacterial pathogens in acidified foods depends not only on the hydrogen ion concentration, but also on the type of acid and the storage temperature. shigella flexneri is a foodborne pathogen that is acid tolerant. the survival of s. flexneri 5348 in brain heart infusion broth supplemented with 0.04 m acetic, citric, lactic, malic, or tartaric acid and adjusted to ph 4 with hci or naoh was studied. the control medium was brain heart infusion broth adjusted to ph 4 with hci. statio ...	2002	12233851
survival and growth of shigella flexneri, salmonella enterica serovar enteritidis, and vibrio cholerae o1 in reconstituted infant formula.	formula feeding is an alternative method to prevent mother-to-child infection with human immunodeficiency virus through breast-feeding in developing countries. growth of bacterial pathogens in reconstituted infant formula has become a health hazard when contaminated water is used for rehydration. this study was conducted to assess bacterial safety risk of using contaminated water to reconstitute infant formula. survival and growth characteristics were determined for three bacterial pathogens, vi ...	2002	12224592
salmonella, shigella and growth potential of other food-borne pathogens in ethiopian street vended foods.	to evaluate the bacteriological safety of food items sold by street vendors with regard to salmonella and shigella and to assess the growth potential of some foodborne pathogens in some street foods.	2001	12219962
three modifications in the d and t arms of trna influence translation in escherichia coli and expression of virulence genes in shigella flexneri.	the modified nucleosides 2'-o-methylguanosine, present at position 18 (gm18), 5-methyluridine, present at position 54 (m(5)u54), and pseudouridine, present at position 55 (psi55), are located in the d and t arms of trnas and are close in space in the three-dimensional (3d) structure of this molecule in the bacterium escherichia coli. the formation of these modified nucleosides is catalyzed by the products of genes trmh (gm18), trma (m(5)u54), and trub (psi55). the combination of trmh, trma, and ...	2002	12218021
sequence analysis and characterization of plasmid psfd10 from salmonella choleraesuis.	the nucleotide sequence of a small plasmid, designated psfd10, is isolated from the vaccine strain salmonella choleraesuis c500 in china, has been determined. this plasmid is 4091 bp long with a total g+c content of 51.4%, which is in the range of salmonella genomic dna. analysis of the complete nucleotide sequence reveals that psfd10 has a high degree of similarity to cole1-type plasmid, having the possible cer and rom genes, and a putative mobilization origin of cole1-type. plasmid psfd10 poss ...	2002	12206756
initial steps of shigella infection depend on the cholesterol/sphingolipid raft-mediated cd44-ipab interaction.	shigellosis is an acute inflammatory bowel disease caused by the enteroinvasive bacterium shigella: upon host cell-shigella interaction, major host cell signalling responses are activated. deciphering the initial molecular events is crucial to understanding the infectious process. we identified a molecular complex involving proteins of both the host, cd44 the hyaluronan receptor, and shigella, the invasin ipab, which partitions during infection within specialized membrane microdomains enriched i ...	2002	12198147
enteroinvasive escherichia coli virulence-plasmid-carried apyrase (apy) and ospb genes are organized as a bicistronic operon and are subject to differential expression.	in shigella flexneri and enteroinvasive escherichia coli (eiec) the expression of the virulence-plasmid(pinv)-carried potential pathogenesis-associated apy gene, which encodes apyrase (atp diphosphohydrolase), is regulated by the same regulators that govern the expression of virulence genes. to understand the transcriptional organization of the apy gene, the authors sequenced an 8023 bp psti fragment of the pinv of eiec strain hn280, which encompasses apy as well as its adjacent genes. the psti ...	2002	12177345
acid tolerance of shigella sonnei and shigella flexneri.	determination of the behaviour of shigella sonnei and sh. flexneri under acid conditions.	2002	12174047
identification of a putative pathogenicity island in shigella flexneri using subtractive hybridisation of the s. flexneri and escherichia coli genomes.	the genetic differences between the human pathogen, shigella flexneri, and the non-pathogenic escherichia coli were investigated in an attempt to identify pathogenicity islands (pais) in the s. flexneri genome. genomic subtraction identified a large unique region of dna which was present in s. flexneri serotype 2a but absent from e. coli k-12. this 42-kb dna segment was localised to the s. flexneri chromosome and was found to contain a number of elements often associated with pais including: ins ...	2002	12167547
bacterial inactivation by high-pressure homogenisation and high hydrostatic pressure.	the resistance of five gram-positive bacteria, enterococcus faecalis, staphylococcus aureus, lactobacillus plantarum, listeria innocua and leuconostoc dextranicum, and six gram-negative bacteria, salmonella enterica serovar typhimurium, shigella flexneri, yersinia enterocolitica, pseudomonas fluorescens and two strains of escherichia coli, to high-pressure homogenisation (100-300 mpa) and to high hydrostatic pressure (200-400 mpa) was compared in this study. within the group of gram-positive bac ...	2002	12160080
isolation of shigella dysenteriae type 1 and s. flexneri strains from surface waters in bangladesh: comparative molecular analysis of environmental shigella isolates versus clinical strains.	bacillary dysentery caused by shigella species is a public health problem in developing countries including bangladesh. although, shigellae-contaminated food and drinks are often the source of the epidemic's spread, the possible presence of the pathogen and transmission of it through environmental waters have not been adequately examined. we analyzed surface waters collected in dhaka, bangladesh, for the presence of shigellae by a combination of pcr assays followed by concentration and culturing ...	2002	12147489
rapid detection of six types of bacterial pathogens in marine waters by multiplex pcr.	a rapid multiplex pcr (m-pcr) method that allows the simultaneous detection, in a single tube, of six commonly encountered waterborne pathogens is developed. the target genes used were: the aerolysin (aero) gene of aeromonas hydrophila, the invasion plasmid antigen h (ipah) gene of shigella flexneri, the attachment invasion locus (ail) gene of yersinia enterocolitca, the invasion plasmid antigen b (ipab) gene of salmonella typhimurium, the enterotoxin extracellular secretion protein (epsm) gene ...	2002	12146868
mxie regulates intracellular expression of factors secreted by the shigella flexneri 2a type iii secretion system.	the mxi-spa locus on the virulence plasmid of shigella flexneri encodes components of the type iii secretion system. mxie, a gene within this locus, encodes a protein that is homologous to the arac/xyls family of transcriptional regulators, but currently its role in pathogenesis remains undefined. we characterized the virulence phenotype of a nonpolar mxie mutant and found that this mutant retained the ability to invade mammalian cells in tissue culture and secrete ipas (type iii effectors requi ...	2002	12142411
quadrupole ion-trap mass spectrometry to locate fatty acids on lipid a from gram-negative bacteria.	the structure of lipid a released by mild acid hydrolysis from lipopolysaccharide from two strains of shigella flexneri with different degrees of acylation was characterized using electrospray ionization (esi) and ion-trap mass spectrometry. the lipid a was analyzed underivatized with esi in negative-ion mode. with multiple stages of fragmentation (ms(n)), both the degree of acylation and the positions of the fatty acids on the disaccharide backbone could be determined. it was possible to determ ...	2002	12137789
[a fatal case of shigellosis in an elderly patient].	a 71 year-old male, with no recent history of travelling abroad and a past history of lung cancer two years prior to presentation, which had been successfully treated, developed a sudden onset of watery diarrhea more than ten times a day on february 26, 2001, which gradually became bloody. the next day he visited the department of integrated medicine of the tokyo metropolitan komagome hospital by ambulance because his consciousness was deteriorating and he was hospitalized. he was hypotensive on ...	2002	12136656
identification of chromosomal shigella flexneri genes induced by the eukaryotic intracellular environment.	upon entry into the eukaryotic cytosol, the facultative intracellular bacterium shigella flexneri is exposed to an environment that may necessitate the expression of particular genes for it to survive and grow intracellularly. to identify genes that are induced in response to the intracellular environment, we screened a library containing fragments of the s. flexneri chromosome fused to a promoterless green fluorescent protein gene (gfp). bacteria containing promoter fusions that had a higher le ...	2002	12117948
prevalence of the genes for shigella enterotoxins 1 and 2 among clinical isolates of shigella in israel.	two enterotoxins, shigella enterotoxin 1 (shet1) and shigella enterotoxin 2 (shet2) have been recently characterized and are believed to play a role in the clinical manifestation of shigellosis. one hundred and twenty-one isolates of shigella spp. of 13 different serotypes and variants and 10 isolates of enteroinvasive escherichia coli (eiec) isolated in israel, were examined by polymerase chain reaction for the presence of shet1 and shet2 genes. shet1 was only prevalent among isolates of s. fle ...	2002	12113500
phenotypic and genotypic characterization of serologically atypical strains of shigella flexneri type 4 isolated in dhaka, bangladesh.	twenty-one atypical shigella flexneri type 4 strains isolated from patients attending the dhaka treatment center of the international centre for diarrhoeal disease research, bangladesh, were extensively characterized and compared with s. flexneri serotypes 4a and 4b. the atypical strains agglutinated only with the type antigen factor 4 and did not agglutinate with any group factors, thereby excluding their characterization into serotype 4a or 4b. of the 21 strains, 85.7% did not ferment mannitol ...	2002	12089268
[development of vaccine for enterohemorrhagic escherichia coli infection].	efforts on the development of vaccines against enterohemorrhagic escherichia coli (ehec) infection has been described in this review. two kinds of vaccines were developed and these have been targeted for in humans and cattle. one vaccine candidate is toxoid, which uses an inactive form of shiga toxin(stx). a part of b subunit, each b or a subunit or one or two amino acid mutated holotoxin were developed as a toxoid vaccine candidate. the other candidate was bacterial surface antigen such as a li ...	2002	12078077
shigella flexneri regulates tight junction-associated proteins in human intestinal epithelial cells.	shigella spp. are a group of gram-negative enteric bacilli that cause acute dysentery in humans. we demonstrate that shigella flexneri has evolved the ability to regulate functional components of tight junctions after interaction at the apical and basolateral pole of model intestinal epithelia. in the regulation of tight junctional protein assemblies, s. flexneri can engage serotype-specific mechanisms, which targets not only expression, but also cellular distribution and membrane association of ...	2002	12067320
human monocytes kill shigella flexneri but then die by apoptosis associated with suppression of proinflammatory cytokine production.	shigella flexneri infection of human macrophages is followed by rapid bacterial escape into the cytosol and secretion of ipab, which activates caspase-1 to mediate cell death and release of mature interleukin (il)-1 beta. here we report a different outcome following infection of human peripheral blood monocytes. s. flexneri infects monocytes inefficiently in the absence of complement and, following complement-dependent uptake, cannot escape the endosomal compartment. consequently, bacteria are k ...	2002	12065527
spa32 regulates a switch in substrate specificity of the type iii secreton of shigella flexneri from needle components to ipa proteins.	type iii secretion systems (ttss) are essential virulence determinants of many gram-negative bacteria and serve, upon physical contact with target cells, to translocate bacterial proteins directly across eukaryotic cell membranes. the shigella ttss is encoded by the mxi/spa loci located on its virulence plasmid. by electron microscopy secretons are visualized as tripartite with an external needle, a transmembrane domain, and a cytoplasmic bulb. in the present study, we generated a shigella spa32 ...	2002	12057936
expression of colonization factor antigen i of enterotoxigenic escherichia coli in shigella flexneri 2a t32.	a host-plasmid lethal balancing system was constructed based on asd gene in an avirulent strain of s.flexneri to express colonization factor antigen i(cfa-i) of enterotoxigenic escherichia coli.the results of western blotting suggested that avirulant strain of s.flexneri fwl01 expressed cfa-i steadily. examination of negatively-stained preparation of cultures by electron microscopy showed that s.flexneri fwl01 carrying the plasmid pzhy21 had thick pili on its surface. antibodies against cfa-i we ...	2001	12050785
[studies on the actin-based spreading of shigella].		2002	12048885
representational difference analysis uncovers a novel is10-like insertion element unique to pathogenic strains of yersinia enterocolitica.	the method of suppressive subtractive hybridization was employed to map out genomic differences between the highly pathogenic yersinia enterocolitica (ye) biogroup 1b, serotype o:8 strain (wa-314) and the closely related apathogenic y. enterocolitica biogroup 1a, serotype o:5 strain (nf-o). a novel is10-like element, is1330, uncovered by this technique was found to be uniquely present in high copy numbers among the highly pathogenic y. enterocolitica 1b strains, while a single copy of the elemen ...	2002	12044683
[molecular characterization of resistance mechanisms to chloramphenicol in shigella flexneri strains isolated from chilean children with acute diarrhea].	chloramphenicol is one of the therapeutic options for shigellosis, but resistance to this antimicrobial is increasing.	2002	12043369
[clinical and morphological aspects of shigellosis flexneri in patients with an aggravated premorbid state].	the analysis of 10 fatal outcomes in patients with acute shigellosis during the period of 1999-2000 made it possible to find out that most of deceased shigellosis patients belonged to the group inclined to alcohol abuse and having initial alimentary disturbances. in 6 cases of acute shigellosis with fatal outcome the causative agent was s. flexneri 2a, in 2 cases--s. flexneri 3a, in 1--s. flexneri 4b. the main cause of fatal outcomes was accompanying double pneumonia. lesions of the intestinal t ...	2002	12043161
antimicrobial resistance of shigella spp isolated from diarrheal patients between 1989 and 1998 in vietnam.	shigellosis is an important cause of infectious diarrhea in vietnam, caused mainly by shigella flexneri. this study provides for the first time in the international literature, data on the development of antimicrobial resistance in shigella between 1988 to 1998, including data reported to the national program for surveillance of antimicrobial resistance (npsar). our studies show that about 80% of the shigella strains tested were resistant to ampicillin, chloramphenicol, oxytetracycline, trimetho ...	2001	12041563
survivability of shigella dysenteriae type 1 & s. flexneri 2a in laboratory conditions simulating aquatic environment.	information about the duration of survival of shigellae in water is speculative. the present study was undertaken to assess the duration of survival of shigella dysenteriae type 1 and s. flexneri type 2a in the laboratory conditions simulating the aquatic environment, their invasive property and the association of different physico-chemical parameters in the survival process.	2001	12040763
mucosal dna vaccination with highly attenuated shigella is superior to attenuated salmonella and comparable to intramuscular dna vaccination for t cells against hiv.	an immunization strategy using attenuated bacteria to deliver dna vaccine plasmids to mucosal sites may induce protective t cell responses against sexual hiv transmission. in a murine intranasal (i.n.) immunization model, we demonstrate that transiently persistent deltaasd shigella flexneri strain 15d harboring dna vaccines induces hiv- and siv-specific gamma interferon (ifn-gamma) producing cd8+ t cells among splenocytes more efficiently than either a longer persisting deltaarod salmonella typh ...	2002	12036602
inorganic polyphosphate is essential for long-term survival and virulence factors in shigella and salmonella spp.	the importance of inorganic polyphosphate (poly p) and poly p kinase (ppk), the enzyme principally responsible for its synthesis, has been established previously for stationary-phase survival of escherichia coli and virulence in pseudomonas aeruginosa. the gene (ppk) that encodes ppk is highly conserved among many bacterial pathogens, including shigella and salmonella spp. in view of the phylogenetic similarity of the enteropathogens and the frequency with which virulence factors are expressed i ...	2002	12032342
the effect of nacl on survival of shigella flexneri in broth as affected by temperature and ph.	shigella, a major foodborne pathogen, survives well in salt-containing environments. however, systematic data are scarce. we studied the behavior of shigella flexneri 5348 in brain heart infusion broth (ph 4 to 6) containing 0.5 to 8% nacl. stationary-phase cells were inoculated into sterile media at initial concentrations of 6 to 7 log10 cfu/ml and incubated at 12 to 37 degrees c. bacterial population sizes were determined periodically by plate counts. survivor curves were derived from plate co ...	2002	12030287
distinct recent lineages of the stra- strb streptomycin-resistance genes in clinical and environmental bacteria.	we report the linkage of the stra-strb streptomycin-resistance genes with class 1 integron sequences on pstr1, a 75-kb multiple antibiotic-resistance plasmid from shigella flexneri. stra-strb had previously been detected only within tn 5393, a tn 3-family transposon, and on small nonconjugative broad-host-range plasmids such as rsf1010. the geographic range of tn 5393 was also extended to pseudomonas spp. isolated from apple trees in new zealand and soil in the usa. comparative sequence analyses ...	2002	12029529
neutrophil elastase targets virulence factors of enterobacteria.	shigellae cause bacillary dysentery, a bloody form of diarrhoea that affects almost 200 million people and causes nearly 2 million deaths per year. shigella invades the colonic mucosa, where it initiates an acute inflammation, rich in neutrophils, that initially contributes to tissue damage and eventually resolves the infection. neutrophils are phagocytic cells that kill microorganisms but it is unclear how neutrophils control pathogenic bacteria expressing virulence factors that manipulate host ...	2002	12018205
death from multi-resistant shigellosis in fiji islands.	death from shigellosis is rare in developed countries, however it causes over a million deaths in developing countries worldwide annually. death from shigellosis is rare in fiji. however, the global problem of emerging multidrug resistance raises some issues about the management of shigellosis in this country. within fiji, shigella is a notifiable disease. the fiji ministry of health recorded 68 cases of shigella in 1996, 173 cases in 1997 and 334 cases in 1998 (no data available for 1999). ther ...	2001	12017845
epidemiological applications: a case report of a village epidemic of gastroenteritis.	this is a case report of an epidemic of gastroenteritis which was investigated and controlled by epidemiological methods only, before laboratory investigations could be done to confirm the original epidemiological conclusions--from contaminated home made ice-cubes. the case and process are reported in order to encourage similar uses of epidemiology by field public health practitioners, especially within the district or primary health care systems and particularly in places where laboratory suppo ...	2001	12017811
the dynamics of actin-based motility depend on surface parameters.	in cells, actin polymerization at the plasma membrane is induced by the recruitment of proteins such as the arp2/3 complex, and the zyxin/vasp complex. the physical mechanism of force generation by actin polymerization has been described theoretically using various approaches, but lacks support from experimental data. by the use of reconstituted motility medium, we find that the wiskott aldrich syndrome protein (wasp) subdomain, known as vca, is sufficient to induce actin polymerization and move ...	2002	12015607
construction, characterization, and animal testing of wrsd1, a shigella dysenteriae 1 vaccine.	wrsd1 is a shigella dysenteriae 1 vaccine containing deletions of the virg(icsa) gene required for intercellular spreading and a 20-kb chromosomal region encompassing the shiga toxin genes (stxab). wrsd1 was constructed from s. dysenteriae 1 strain 1617 that was originally isolated during the 1968 to 1969 epidemic of shiga dysentery in guatemala. the virg(icsa) deletion was constructed from a streptomycin-resistant (str(r)) mutant of 1617 by a filter mating procedures using a virg(icsa) deletion ...	2002	12010984
regulation of the overlapping pic/set locus in shigella flexneri and enteroaggregative escherichia coli.	most strains of shigella flexneri 2a and enteroaggregative escherichia coli carry a highly conserved chromosomal locus which encodes a 109-kda secreted mucinase (called pic) and, on the opposite strand in overlapping fashion, an oligomeric enterotoxin called shet1, encoded by the seta and setb genes. here, we characterize the genetic regulation of these overlapping genes. our data suggest that pic and the setba loci are transcribed as complementary 4-kb mrna species. the major pic promoter is ma ...	2002	12010980
rhamnose-binding lectins from steelhead trout (oncorhynchus mykiss) eggs recognize bacterial lipopolysaccharides and lipoteichoic acid.	the interaction between bacteria and three l-rham-nose-binding lectins, named stl1, stl2, and stl3, from steelhead trout (oncorhynchus mykiss) eggs was investigated. although stls bound to most gram-negative and gram-positive bacteria, they agglutinated only escherichia coli k-12 and bacillus subtilis among the bacteria tested. the binding was inhibited by l-rhamnose. stls bound to distinct serotypes of lipopolysaccharides (lpss), and showed much higher binding activities to smooth-type lpss of ...	2002	12005056
incidence and molecular analysis of vibrio cholerae associated with cholera outbreak subsequent to the super cyclone in orissa, india.	an epidemiological study was carried out to find out the aetiological agent for diarrhoeal disorders in the cyclone and flood affected areas of orissa, india. rectal swabs collected from 107 hospitalized diarrhoea patients were bacteriologically analysed to isolate and identify the various enteropathogens. detection of toxic genes among e. coli and v. cholerae was carried out by polymerase chain reaction (pcr) assay. of the 107 rectal swabs analysed, 72.3% were positive for v. cholerae o1 ogawa, ...	2002	12002529
two msbb genes encoding maximal acylation of lipid a are required for invasive shigella flexneri to mediate inflammatory rupture and destruction of the intestinal epithelium.	shigella flexneri is a gram-negative pathogen that invades and causes inflammatory destruction of the human colonic epithelium, thus leading to bloody diarrhea and dysentery. a type iii secretion system that delivers effector proteins into target eukaryotic cells is largely responsible for cell and tissue invasion. however, the respective role of this invasive phenotype and of lipid a, the endotoxin of the shigella lps, in eliciting the inflammatory cascade that leads to rupture and destruction ...	2002	11994481
bromoperoxidase activity of vanadate-substituted acid phosphatases from shigella flexneri and salmonella enterica ser. typhimurium.	vanadium haloperoxidases and the bacterial class a nonspecific acid phosphatases have a conserved active site. it is shown that vanadate-substituted recombinant acid phosphatase from shigella flexneri (phon-sf) and salmonella enterica ser. typhimurium (phon-se) in the presence of h2o2 are able to oxidize bromide to hypobromous acid. vanadate is essential for this activity. the kinetic parameters for the artificial bromoperoxidases have been determined. the km value for h2o2 is about the same as ...	2002	11985594
development of an oral prime-boost strategy to elicit broadly neutralizing antibodies against hiv-1.	given the increasing incidence of hiv-1 infection world-wide, an affordable, effective vaccine is probably the only way that this virus will be contained. accordingly, our group is developing an oral prime-boost strategy with the primary goal of eliciting broadly neutralizing antibodies against hiv-1 to provide sterilizing immunity for this virus. our secondary goal is to elicit broadly cross-reactive anti-viral cd8(+) t cells by this strategy to blunt any breakthrough infections that occur afte ...	2002	11983256
cytotoxicity and interleukin-1beta processing following shigella flexneri infection of human monocyte-derived dendritic cells.	shigella flexneri infection of macrophages (mphi) leads to activation of caspase-1 by the ipab virulence factor, which induces rapid cell death and release of mature il-1beta. here we show that s. flexneri infection of human monocyte-derived dendritic cells (dc) also results in rapid ipab-dependent death. cytotoxicity is only partially blocked by the caspase-1 inhibitor yvad, but completely blocked by the pan-caspase inhibitor z-vad. cytotoxicity is also partially blocked by glycine without affe ...	2002	11981835
quantification of shigella icsa required for bacterial actin polymerization.	shigella move through the cytoplasm of host cells by active polymerization of host actin to form an "actin tail." actin tail assembly is mediated by the shigella protein icsa. the process of shigella actin assembly has been studied extensively using icsa-expressing escherichia coli in cytoplasmic extracts of xenopus eggs. however, for reasons that have been unclear, wild type shigella does not assemble actin in these extracts. we show that the defect in actin assembly in xenopus extracts by shig ...	2002	11977093
characterization of pecl18 and pkpn2: a proposed pathway for the evolution of two plasmids that carry identical genes for a type ii restriction-modification system.	the primary structures of the plasmids pecl18 (5571 bp) and pkpn2 (4196 bp) from escherichia coli and klebsiella pneumoniae, respectively, which carry genes for a type ii restriction-modification system (rms2) with the specificity 5'-ccngg-3', were determined in order to elucidate the structural relationship between them. the data suggest a possible role for recombination events at bom (basis of mobility) regions and the sites of resolution of multimer plasmid forms (so-called cer sequences) in ...	2002	11976960
genomic subtraction to identify and characterize sequences of shiga toxin-producing escherichia coli o91:h21.	to identify shiga toxin-producing escherichia coli genes associated with severe human disease, a genomic subtraction technique was used with hemolytic-uremic syndrome-associated o91:h21 strain ch014 and o6:h10 bovine strains. the method was adapted to the shiga toxin-producing e. coli genome: three rounds of subtraction were used to isolate dna fragments specific to strain ch014. the fragments were characterized by genetic support analysis, sequencing, and hybridization to the genome of a collec ...	2002	11976103
regulation of transcription by the activity of the shigella flexneri type iii secretion apparatus.	the virulence plasmid-encoded type iii secretion system of shigella flexneri consists of the mxi-spa secretion apparatus, secreted proteins ipaa-d and ipgd involved in entry of bacteria into epithelial cells,cytoplasmic chaperones ipgc and ipge and 15 other secreted proteins of unknown function, including vira and members of the ipah family. the activity of the mxi-spa apparatus is regulated by external signals, and transcription of vira and ipah genes is specifically induced in conditions of ac ...	2002	11971264
spa15 of shigella flexneri, a third type of chaperone in the type iii secretion pathway.	the type iii secretion (tts) pathway is used by numerous gram-negative pathogens to inject virulence factors into eukaryotic cells. in addition to a functional tts apparatus, secretion of effector proteins depends upon specific chaperones. using a two-hybrid screen in yeast and a co-purification assay in shigella flexneri, we demonstrated that spa15, which is encoded by an operon for components of the tts apparatus, is associated in the cytoplasm with three proteins that are secreted by the tts ...	2002	11952903
neural wiskott-aldrich syndrome protein (n-wasp) is the specific ligand for shigella virg among the wasp family and determines the host cell type allowing actin-based spreading.	shigella, the causative agent of bacillary dysentery, is capable of directing its movement within host cells by forming an actin comet tail. the virg (icsa) pro-tein expressed at one pole of the bacterium recruits neural wiskott-aldrich syndrome protein (n-wasp), a member of the wasp family, which in turn stimulates actin-related protein (arp) 2/3 complex-mediated actin polymerization. as all the wasp family proteins induce actin polymerization by recruiting arp2/3 complex, we investigated their ...	2002	11952639
[phenomenon of apoptosis in the survival of enterobacteria in the parasite-host system].	data on the apoptosis phenomenon with enterobacteria used as a model are presented. one of the mechanisms regulating the vital activity of eukaryotic cells is, together with cell proliferation and differentiation, the phenomenon known as "apoptosis". this physiological process of the eukaryotic cells death is used by many parasites in parasite--host relationships in different epitopes. the system known to trigger programmed cell death, is the surface receptor fas, the receptor of tumor necrosis ...	2002	11949266
studies on o-specific polysaccharides of shigella flexneri 1b(i) and its smooth mutant z(iii).		1970	11947597
the infrared spectroscopic gram stain.	the attenuated total reflectance (atr) spectra of bacterial colonies were obtained in situ, without their removal from the agar growth media using the infrared microscope. principal components regression (pcr) analysis was used to obtain a measure of the differentiating potential of the atr spectra obtained on two standard sets consisting of 31 and 44 species, respectively, grown on trypticase soy agar. a quantitative response value of +1 was assigned to gram positive species and -1 was assigned ...	2001	11936876
development of a p1 phagemid system for the delivery of dna into gram-negative bacteria.	the inability to transform many clinically important gram-negative bacteria has hampered genetic studies addressing the mechanism of bacterial pathogenesis. this report describes the development and construction of a delivery system utilizing the broad-host-range transducing bacteriophage p1. the phagemids used in this system contain a p1 pac initiation site to package the vector, a p1 lytic replicon to generate concatemeric dna, a broad-host-range origin of replication and an antibiotic-resista ...	2002	11932441
prevalence of the sat gene among clinical isolates of shigella spp. causing travelers' diarrhea: geographical and specific differences.		2002	11923399
wild-type intracellular bacteria deliver dna into mammalian cells.	gene transfer in vitro from intracellular bacteria to mammalian phagocytic and non-phagocytic cells and in vivo in mice has been reported. the bacteria used as dna delivery vectors were engineered to lyze upon entry in the cell due to impaired cell wall synthesis for shigella flexneri and invasive escherichia coli, or production of a phage lysin for listeria mono- cytogenes. in vivo gene transfer was obtained with attenuated salmonella typhimurium and resulted in stimulation of mucosal immunity. ...	2002	11906454
the escherichia coli k-12 shea gene encodes a 34-kda secreted haemolysin.	haemolytic toxins belong to one of several classes of virulence factors that contribute to bacterial pathogenicity. the non-pathogenic escherichia coli k-12 laboratory strain was considered for years to be non-haemolytic. however, overproduction of several transcriptional regulators induced the appearance of a haemolytic activity that is absent under usual laboratory growth conditions. in this work, we have cloned and characterized an e. coli k-12 gene, shea, whose overexpression results in a ha ...	1997	11902713
genetic determinants of tetracycline resistance in vibrio harveyi.	isolates of vibrio harveyi, a prawn pathogen, have demonstrated multiple antibiotic resistance to commonly used antimicrobial agents, such as oxytetracycline. in this paper, we describe the cloning and characterization of two tetracycline resistance determinants from v. harveyi strain m3.4l. the first resistance determinant, cloned as a 4,590-bp fragment, was identical to teta and flanking sequences encoded on transposon tn10 from shigella flexneri. the second determinant, cloned as a 3,358-bp f ...	2002	11897587
complete genomic sequence of sfv, a serotype-converting temperate bacteriophage of shigella flexneri.	bacteriophage sfv is a temperate serotype-converting phage of shigella flexneri. sfv encodes the factors involved in type v o-antigen modification, and the serotype conversion and integration-excision modules of the phage have been isolated and characterized. we now report on the complete sequence of the sfv genome (37,074 bp). a total of 53 open reading frames were predicted from the nucleotide sequence, and analysis of the corresponding proteins was used to construct a functional map. the gene ...	2002	11889106
cdc42 facilitates invasion but not the actin-based motility of shigella.	the enteric pathogen shigella utilizes host-encoded proteins to invade the gastrointestinal tract. efficient invasion of host cells requires the stimulation of rho-family gtpases and cytoskeletal alterations by shigella-encoded ipac. following invasion and lysis of the phagosome, shigella exploits the host's actin-based polymerization machinery to assemble an actin tail that serves as the propulsive force required for spreading within and between cells. the shigella surface protein icsa stimulat ...	2002	11864577
[investigation of a shigellosis outbreak in a rural zone of senegal].	the investigation of this outbreak took place in niakhar (ird project study area), a rural area located 150 km east of dakar. covering 30 villages, with a population of about 30,000 inhabitants, the area has been under demographic and epidemiological surveillance. in 1999, the surveillance allowed 973 cases of shigellosis to be recorded out of 1,751 cases of dysenteric diarrhoeas. the outbreak reached a peak during the raining season (73% of the cases in september and october). all the villages ...	2001	11861195
[gena types of shigella enterotoxins of s. flexneri 2a].	to identify homogenous clones of s. flexneri 2a, using gene distribution polymorphism of shigella enterotoxin 1 (set 1) and shigella enterotoxin 2 (set 2) in a shigellosis outbreak caused by s. flexneri 2a.	2000	11860800
shigella flexneri interactions with the basolateral membrane domain of polarized model intestinal epithelium: role of lipopolysaccharide in cell invasion and in activation of the mitogen-activated protein kinase erk.	an early step governing shigella flexneri pathogenesis is the invasion of the colonic epithelium from the basolateral surface followed by disruption of the colonic epithelial barrier. despite recent insight into s. flexneri-host interactions, much remains to be determined regarding the nature of the initial contact between s. flexneri and the host epithelial basolateral membrane domain. since the lipopolysaccharide (lps) is located at the outermost part of the bacterial membrane, we considered t ...	2002	11854195
molecular dissection of virb, a key regulator of the virulence cascade of shigella flexneri.	the virb protein is a key regulator of virulence gene expression in the facultative enteroinvasive pathogen shigella flexneri. while genetic evidence has shown that it is required for activation of transcription of virulence genes located on a 230-kb plasmid in this bacterium, hitherto, evidence that virb is a dna-binding protein has been lacking. although virb shows extensive homology to proteins involved in plasmid partitioning, it does not resemble any known conventional transcription factor. ...	2002	11850420
differentiation of shigella strains by plasmid profile analysis, serotyping and phage typing.	ninety-one shigella flexneri and 29 shigella sonnei strains isolated during 1994 from sporadic cases of shigellosis and healthy carriers were analyzed for plasmid profile in order to compare the discriminating ability of this method with that of serotyping and phage typing. our study revealed 10 plasmid profiles (pp) among s. sonnei strains. a total of 26 out of 29 (89%) s. sonnei isolates could be placed into two phage types (type 1 and 20) comprising four pp for phage type 1 and seven pp for t ...	2000	11845469
shigella spa32 is an essential secretory protein for functional type iii secretion machinery and uniformity of its needle length.	the shigella type iii secretion machinery is responsible for delivering to host cells the set of effectors required for invasion. the type iii secretion complex comprises a needle composed of mxih and mxii and a basal body made up of mxid, mxig, and mxij. in s. flexneri, the needle length has a narrow range, with a mean of approximately 45 nm, suggesting that it is strictly regulated. here we show that spa32, encoded by one of the spa genes, is an essential protein translocated via the type iii ...	2002	11844752
chronic vulvovaginitis caused by antibiotic-resistant shigella flexneri in a prepubertal child.	a 7-year 8-month-old girl was diagnosed with a prolonged course of vulvovaginitis caused by shigella flexneri. the child was symptomatic with intermittent vaginal bleeding, dysuria and foul smelling vaginal discharge for a 3-year period. initial attempts to resolve the infection with successive courses of antibiotic therapy using ampicillin, trimethoprim-sulfamethoxazole, cefixime and amoxicillin/clavulanic acid failed. the child's infection was finally resolved by a 14-day course of ciprofloxac ...	2002	11840089
synthesis and evaluation of antibacterial activity of some 2-[[alpha-(4-substituted benzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)- 1,3,4-oxadiazoles.	in this study, a new series of 1-[[alpha-(4-substitutedbenzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles were obtained by condensation of 2-[(alpha-chloro-alpha-phenylacetyl or alpha-bromopropionyl)amino]-5-(4-methoxyphenyl)1,3,4-oxadiazoles with sodium salts of 4-substituted benzoic acids. structures of the compounds were assigned on the basis of spectral data (uv, ir, 1h nmr, el ms) and elemental analyses. the antibacterial activities of the novel comp ...	2001	11829119
synthesis and antimicrobial activity of some 1,2,4-triazole-3-mercaptoacetic acid derivatives.	ethyl 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetate (2), 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazide (3) and a series of new n-alkylidene/arylidene-5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazides (4a-f) were synthesized and evaluated for in vitro antibacterial activity against staphylococcus aureus atcc 6538. staphylococcus epidermidis atcc 12228, klebsiella pneumoniae atcc 4352, pseudomonas aeruginosa atcc 1539, escherichia coli atcc 8739, shige ...	2001	11829115
pathogenic effects of opolysaccharide from shigella flexneri strain.	aim:to investigate the specific pathogenesis of o-polysaccharide (o-ps) which is on the outer membrane of lipopolysaccharides (lps) from shigella flexneri.methods:the o-ps was isolated and purified from shigella flexneri 5 m90t by enzymatic hydrolysis and gel chromatography. effects of o-ps were observed by in vitro experiment, (hela cell culture), and in vivo experiment (rabbit ileal loop assay).results:in vitro and in vivo experiments with the purified o-ps from shigella flexneri revealed that ...	1999	11819440
shigella septicaemia in adults: report of two cases and mini-review.	we report 2 cases of shigella septicaemia in adult patients.	2001	11817302
[isolation of provisional serovars of shigella in diarrheal cases of tourists].	twenty-four shigella strains of provisional serovars were isolated from travellers with diarrhea during 1993-2000 at osaka airport- and kansai airport-quarantine station. the outline of these cases were as follows. 1) the provisional serovars of these strains (number of cases) were s. dysenteriae 93-119 (2), s. dysenteriae 204/96 (4), s. dysenteriae i9809-73 (4), s. flexneri 88-893 (9), and s. boydii e16553 (5). 2) symptoms of these cases were diarrhea, abdominal pain, fever, and vomiting. the r ...	2001	11806136
neonatal shigellosis.		2001	11794928
protective role of human lactoferrin against invasion of shigella flexneri m90t.	lactoferrin is an iron-binding protein found in human mucosal secretions such as milk. a variety of functions have been ascribed to this protein, it appears to contribute to antimicrobial host defense. still its overall physiological role remains to be defined. we sought to study the role of recombinant human lactoferrin (rhlf) in shigella infection. invasion of epithelial cells is essential to the development of bacillary dysentery. shigella flexneri 5 m90t, a virulent strain, was evaluated in ...	2001	11787716
differential expression of inducible nitric oxide synthase is associated with differential toll-like receptor-4 expression in chicken macrophages from different genetic backgrounds.	the purpose of this study was to examine inos gene expression and activity in macrophages from different chicken genetic lines against various bacterial lps. furthermore, the possible involvement of surface lps receptors as candidates for differential inos gene induction in these genetic lines of chicken was also examined. sephadex-elicited abdominal macrophages (1 x 10(6)) as well as inos hyper-responder macrophages from a transformed chicken macrophage cell line, mq-ncsu, were exposed to 5 mic ...	2002	11777534
[value of antibiotype and bacteriocinotype for differentiating shigella strains isolated in argentina].	the aim of the present work was to analyse the phenotypical characteristics of shigella strains in order to evaluate their possible utilisation as epidemiological markers. for one year, we studied 95 strains of shigella obtained from stool specimens of patients with dysentery. bacteria came from various health care centres in the states of chaco and corrientes (argentina). bacteria were identified by using classical biochemical methods. all strains were serotyped and susceptibility patterns were ...	2000	11775312
evaluation of culture media for enrichment and isolation of shigella sonnei and s. flexneri.	the performance of gram-negative (gn) broth with (10 microg/ml) and without novobiocin, shigella broth (sb) with 0.5 and 3.0 microg/ml novobiocin, all incubated at 37 degrees c (sb with 3.0 microg/ml novobiocin also at 42 degrees c) and buffered brilliant green bile glucose (ee) broth with 1.0 microg/ml novobiocin incubated at 37 and 42 degrees c were evaluated for resuscitation and growth of shigella sonnei and s. flexneri (eight strains; unstressed, chill-stressed and acid-stressed) and non-sh ...	2001	11764191
epidemiology of shigellosis in lagos, nigeria: trends in antimicrobial resistance.	antimicrobial susceptibility of shigella spp. and escherichia coli, isolated from diarrhoeal patients in lagos, was studied from march 1999 to february 2000. four hundred fifty-nine isolates were identified as shigellae (62) and e. coli (397). shigella flexneri, s. dysenteriae, s. boydii, and s. sonnei accounted, respectively, for 51.6%, 17.7%, 17.7%, and 13% of the total number of shigellae isolated. eleven cases of shigellosis occurred in the age group of 0-9 years, 22 cases in the age group o ...	2001	11761772
blockade of cd14 aggravates experimental shigellosis.	shigella infections lead to severe inflammation associated with destruction of colonic mucosa. we assessed the effect of in vivo blockade of cd14 on the outcome of experimental shigella infection in rabbits. a total of 17 rabbits were divided into two groups: 8 received a single i.v. dose of anti-rabbit cd14 monoclonal antibody prior to infection with an invasive shigella flexneri strain; the remainder served as controls. the anti-cd14-treated rabbits exhibited more severe tissue destruction and ...	2001	11753214
in vivo dna-binding and oligomerization properties of the shigella flexneri arac-like transcriptional regulator virf as identified by random and site-specific mutagenesis.	in shigella flexneri expression of the plasmid-encoded virulence genes is regulated via a complex mechanism involving both environmental signals and specific transactivators. the primary regulator protein, virf, is a member of the arac family of transcription factors and shares with other arac-like proteins a conserved carboxy-terminal domain thought to be important for dna binding. random and site-directed mutagenesis of the virf gene encoding virf yielded a number of mutations along the length ...	2002	11751832